(CNSNews.com) - Many conservatives disagree with President Obama on Iran and just about everything else. But sometimes they also disagree with each other. It happened Wednesday night on Fox News, when Sean Hannity sparred with conservative commentator Patrick Buchanan over Iran.

Hannity said Buchanan is "dreaming" for believing the United States can find "common ground" with Iran because the two countries have mutual enemies.

Buchanan called Hannity "hysterical" for worrying about nuclear weapons in the hands of "radical Islamic mullahs" who engage in bluster and "beer talk."

"You don't see that as a danger?" Hannity asked Buchanan.

"The United States could finish off Iran in an afternoon. What are you frightened of, Sean?" Buchanan asked. He agreed it's a "bad idea" for Iran to get an atomic bomb, "and I think we can stop it."

In one of his recent columns, Buchanan said the alternative to a truce with Iran "inevitably leads to war," something he said neither the Americans nor the Iranians want.Buchanan also highlighted other areas of "common ground" between the U.S.and Iran, including the "common goal" of defeating the Islamic State terrorists and expelling them from Iraq.

Buchanan amplified on those points in his discussion with Hannity Wednesday night:

"Look, in 1956, (Soviet leader Nikita) Khrushchev says, 'We will bury you' Americans, and three years later, he was in the White House with Dwight Eisenhower. You got to talk to your enemies. Ahmadinejad, the former president of Iran, came out and said, We're going to wipe Israel off the map. It was beer talk."

"Pat, that's not beer talk!" Hannity exclaimed. "You don't believe them? Wasn't that a mistake we made in World War II, that the only person that seemed to really understand the nature of Hitler's ambitions was a guy by the name of Winston Churchill? Wasn't he the one guy that understood...

"Sean, Ahmadinejad was in power for eight years. He did nothing. He was a blowhard. Are we going to be frightened by words from some character in Iran?"

Hannity noted that the blowhard's nation has supplied rockets to Hezbollah and other terror groups to "fight a proxy war against Israel."

Buchanan said the Iranians "are not our friends," but "they're fighting our enemies. I'd rather have Iranians up there fighting in Tikrit and dying than American kids there."

Hannity, interrupting, asked Buchanan why he doesn't have a problem with Iran, a state sponsor of terror, getting a nuclear weapon, fighting proxy wars and threatening to annihilate Israel and promising death to the United States.

"You have no problem with that?!" Hannity asked.

"Listen to the...American head of intelligence," Buchanan replied. "He says Iran does not have a bomb program as of 2013. Secondly, if they start building a bomb, we will know it. Third, Iran has made some concessions, though not enough, that makes them less able to get to a bomb."

Buchanan noted that Israeli Prime Minister Bibi Netanyahu has been talking about Iran getting a bomb since 1992. "In 2006, he said they'll be building 25 bombs by the end of the decade. Are they? No."

What about Iran's ambitions to "build a huge power for themselves in the region," Hannity asked.

"Sean, the reason Iran's going to be a power in the Gulf is because your president, George W. Bush, invaded Iraq and turned it into a (satellite) of Iran...The reason we're in this position is because Saddam Hussein, a thug, was overthrown. His state was destroyed. His army was broken up. Elections were held by Bush -- democracy crusades...and the Shia won. And we lost Iraq!"

"You believe that we can make a deal with the Iranians. You believe peace with the Iranians in our time! Is that what you're saying?" Hannity asked.

"No, I'm not scared of Iran, for God's sakes. They don't have an atomic bomb."

"Now you sound like Obama! Iran is a tiny country. They're not a threat. You believe that?" Hannity asked.

"Bibi's sitting on 200 atom bombs and he's fretting over Iran, which hasn't even produced weapons-grade uranium," Buchanan replied.

"And this is going to create...an arms race that the likes of which the world has never seen," Hannity responded.

"Oh, cut it out, Sean...The United States could finish off Iran in an afternoon. What are you frightened of, Sean?"

"Just like we finished off North Korea in an afternoon, right, Pat? I think you're dreaming."